(As always, click on images to enlarge) The jet stream will feature a broad and deep trough in this forecast period, and this will allow deep cold that's been reloading in Canada to surge southward. This air will be 20 to 30 degrees Farenheit below normal, meaning some parts of the Northern United States will find temperatures struggling to surpass zero, with widespread wind chill values below zero extending as far south as the Tennessee River Valley and Mid-Atlantic United States.
Meanwhile, I expect several upper level disturbances to continue traversing the country in active Westerly winds. At first, these disturbances won't produce more than snow showers and orographically (terrain) enhanced squalls with their passage, as the relatively dry, arctic air will keep deeper moisture surpressed southward. From midweek onward in the forecast period, however, the cold and dry airmass relents just enough to open the door to more moisture, and I do expect this to prompt at least one Eastern U.S. storm/Northeast U.S. snowstorm, hence the forecast for above normal precipitation.
